Improvement in chimney-cowls



UNITEn STATES PATENT OEEroE.

OF SAME PLAGE.

IMPROVEMENT IN CHIMNEV-COWLS.

Specification forming part of Letters Patent No. 117,129, dated July 18, 1871.

` in the county of Suifoll; and State of Massachusetts, have invented a new and useful Improvement on Ventilators; and I do hereby declare that the following is a full and exact description, reference being had to the drawing making part of this specification.

Figure 1 is a perspective view. Fig. 2 is a horizontal, and Fig. 3 a perpendicular section of my invention, which consists of a flue-pipe, A, corrugated shield B, and semi-cone O, D D being braces or wings used to support and connect B and C with A. Any other mode of securing B and O in the proper place in relation to fluepipe A will answer the same purpose. The distance between iiue-pipeA and semi-cone() should be about three-quarters of the diameter of fluepipe A. The larger diameter of the semi-cone O must overlap flue-pipe A one inch, so that water may drip clear of flue pipe A. The smaller diameter of semi-cone C should be one-half the diameter of flue-pipe A, and the semi-cone may be plain or an uneven surface on the edges. A cone forms a cheek to the draught, whereas the semi-cone affords relief, and at the same time forms a perfect shield against the weather when set down within the outer shield, as shown ,in Figs. l and 3. The diameter of corrugated shield B should be sufficient for the area between shield B and semi-cone C to be as great as the area of the diameter of iiue-pipe A. The effect of the corrugations on shield B is to cause the wind to rebound from the surface, helping to cause a vacuum within the shield, thereby producing a draught, the result attained being a free and unimpeded outlet and the greatest possible protection against wind and weather.

What I claim as new, and wish to secure by Letters Patent, :ls-

l. The corrugated shield B, as and for the purpose specified. g

2. The combination of the flue-pipe A, corrugated shield B, and semi-cone G, as and for the purpose specied.

3. In combination with the flue-pipe A, the semi-cone O, when arranged and combined in the manner and for the purpose as specified.

JOHN WALKER.

Witnesses:

CHARLES BRENNAN, E. M. PUTNAM. 

